1. Field of the Invention
This invention relates to a two-shaft continuous mixing apparatus.
2. Description of the Prior Art
In the above-mentioned two-shaft continuous mixing apparatus, it is generally customary that a discharge control device (a gear pump) for discharging materials to be mixed is connected outside of the mixed material discharge port provided on one end in the longitudinal direction of a housing, and further a pelletizer is installed on the discharge side of the apparatus. That is, apparatus for forming the mixed materials such as plastics and rubber materials are consecutively arranged.
In this case, the following types of two-shaft continuous mixing apparatus are known, which vary mainly with the way of setting the positional relationship of the housing and the gear pump.
First, the apparatus of the type shown in FIG. 5 is a so-called downward discharge type. In this drawing, a numeral 20 refers to a housing of the mixing apparatus. In a mixing chamber 21 defined within this housing 20 are rotatably installed two rotors 22 and 23 arranged in a horizontal direction. A numeral 24 denotes a gear pump, which is directly coupled with the housing 20 immediately below a discharge port 25, and mounted on the floor 26 of a second floor. A numeral 27 designates a pelletizer, which is installed on the floor 28 of a first floor and connected with the discharge side of the gear pump 24 by means of a transfer pipeline 29 (Japanese Patent Publication No. 56-3091).
Next, FIG. 6 shows a lateral discharge type two-shaft continuous mixing apparatus all set up on the floor 28 of the first floor, in which the housing 20 of the downward discharge type described above is installed with the rotors vertically arranged. On the side of the housing 20 the gear pump 24 and the pelletizer 27 are connected sidewise.
Finally, FIG. 7 shows the two-shaft continuous mixing apparatus of an inclined lateral discharge type according to the present invention, which is of an inclined lateral discharge type. As is shown in this drawing, the housing 20 is inclined by about 45 degrees and the gear pump 24 and the pelletizer 27 connected to the housing 20 are both coupled in juxtaposition with each other similarly to the above-described lateral discharge type (Specification and drawings in Japanese Patent Application No. 61-172096).
These prior arts have made a progress in order of mention.
For example, the above-described downward discharge type required a large-size plant due to an increase particularly in machine height. This problem has been solved by the use of the lateral discharge type in which the housing 20 is vertically arranged. This lateral discharge type, however, still had such a disadvantage as a lowered feed capacity of the rotors 22 and 23 and a non-uniform material temperature within the mixing chamber 21 caused by the adoption of the vertical arrangement of the housing 20. Both the above-described problems and disadvantages have been simultaneously solved by the adoption of the inclined lateral discharge type without accompanying an increase in the plant size.
In the inclined lateral discharge type, however, the housing 20, being inclined 45 degrees as shown in FIG. 7, has become complicated in construction and consequently costly. Further, a facility for replacing the rotors 22 and 23 requires troublesome maintenance work.
Furthermore, the twin rotors 22 and 23 are desired to be horizontally arranged in order to perform mixing operation most satisfactorily. In this respect, therefore, the above-described types of mixing apparatus can not fully obviate these problems and disadvantages.